More fully in Etymologicum Magnum 60.48-50: "a spring in Ephesos, so called from its never providing too little or too much, whether in winter or summer. Methodios [sc. says this]".
For Ephesos cf. epsilon 3864.
David Whitehead (added note; cosmetics) on 28 January 2001@06:57:55. David Whitehead (expanded note) on 2 August 2011@04:13:07. David Whitehead (expanded and modified note) on 5 February 2012@06:36:26. Catharine Roth (cosmetics) on 31 May 2015@00:01:42.